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Tersicore
Stereo Power Amplifier
User Manual
Important Safety Instructions
1. Read these instructions.
2. Save these instructions.
3. Pay attention to all advice.
4. Always follow instructions.
5. Do not use this unit in presence of water.
6. Clean with a dry cloth only.
7. Do not obstruct venting holes and heat sinks. Install as indicated by the manufacturer.
8. Do not install near heat sources as heaters, heat pumps, stoves or other equipment which produces
heat.
9. Do not alter the functionality of a polarized plug or of one provided with earth connection. A plug is
polarized when it can be fitted in the mains socket in one way only. A plug provided with earth
connection has two prongs for current and a third one for earth connection. The latter is provided for
user’s safety. If the plug provided doesn’t fit your mains socket, consult a technician to obtain the
replacement of the obsolete mains socket.
10. The mains cable represents the emergency detachment device for this unit. It’s important to grant a
quick access to this cable in every moment.
11. Protect the mains cable against trampling and mashing, particularly close to the plug and to the
connector at the unit’s input socket.
12. Only use connectors and accessories specified by the manufacturer.
13. Only use the cart, stand, tripod or table specified by the manufacturer or sold with the unit. When
using a cart, pay attention while shifting the cart/unit ensemble to avoid harming people or flipping
the cart upside down.
14. Isolate the unit from mains during lightning storms or when it’s not operated for long.
15. Refer all servicing to qualified personnel. Servicing is required when the unit is damaged due to any
reason, e.g. when mains cable or plug are damaged, when a liquid is spilled on the unit or when
objects drop on it, when the unit is exposed to rain or moisture, or when it is not operative or when it
has been dropped from whatever height. The replacement of the outer shell must be considered a
service operation.
16. Venting must not be impeded by obstructing venting holes and heat sinks with objects like
newspapers, towels, curtains and the like.
17. Do not place any free flame, like a candle or the like, on the unit.
18. Terminals marked with this label must be considered DANGEROUS and the connections external to
these terminals require servicing by a TRAINED TECHNICIAN or the use of factory prepared
cables.
Warning!
To reduce the risk of fire or electric shock, do not expose this unit to rain or
moisture. Do not place objects containing liquids, like bowls or glasses, on this
unit.
2
Warning!
Changes or modifications not authorized by the manufacturer can invalidate the
compliance to CE regulations and cause the unit not to be suitable to use any
longer. The manufacturer rejects any responsibility regarding damages to people or
things due to the use of a unit which has been subject to unauthorized
modifications or to misuse or to malfunction of a unit which has been subject to
unauthorized modifications.
3
Instructions for Recycling
The label on the left, printed on the envelope of the product, indicates that the product,
when no more usable, can’t be treated as generic garbage, but must be disposed of at a
collection point for recycling of electrical and electronic equipment, in compliance with
the WEEE regulation (Waste of Electrical and Electronic Equipment).
By making sure that this unit is correctly recycled, you will help preventing potential
damages to environment and to human health. Recycling helps saving natural resources.
For more information about recycling this product, please contact Absoluta Sound and
Space Srl.
ABSOLUTA SOUND AND SPACE
Galleria Andrea Urbani, 3
35027 Noventa Padovana (PD)
Ph. :
Fax.
Web:
+39.049.8935377
+39.049.8935377
www.absoluta.it
Customer Service
Phone:
+39.049.8935377
Fax:
+39.049.8935377
e-mail:
[email protected]
P/N: 1234557 – Rev. 1.0 – 03/09
“Absoluta Sound and Space” and the logo Absoluta
are registered trademarks of Absoluta Sound and
Space Srl.
© Absoluta Sound and Space Srl. All right reserved.
This manual should not be construed as a
commitment on the part of Absoluta Sound and
Space Srl. The information it contains is subject to
changes without notice. Absoluta Sound and Space
assumes no responsibility for errors that may appear
within this document.
4
Safety Terms and Symbols
This document contains instructions on generic safety,
installation and use for the Tersicore stereo power amplifier. It
is important to read this document before trying to use this
amplifier. Pay particular attention to safety instructions.
Appears on the unit to indicate the presence
of uninsulated, dangerous voltages inside
the enclosure - voltages sufficient to constitute
a risk of shock.
Appears on the unit to indicate important
operation or maintenance instructions included
in the accompanying documentation.
Appears on the unit to indicate compliance
with the EMC (Electromagnetic Compatibility
and LVD (Low-voltage Directive) standards
of the European Union.
Warning!
Calls for attention to a procedure, practice
condition, or the like that, if not correctly
performed or adhered to, could result in
personal injuries, death or damages to the unit
or to other objects.
Note
Calls for attention to information that is
essential to highlight
5
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6
Table of Contents
Introduction .....................................................................9
Special Design Features...................................................9
Unpacking.......................................................................12
Installation Considerations..............................................13
Power Requirements ......................................................15
Operation.......................................................................17
Back Panel......................................................................17
Connections ....................................................................22
Base Connection Set-up .................................................24
Base Balanced Connection.............................................25
Passive Bi-amping Connection .......................................25
Bridge Connection ..........................................................26
Troubleshooting............................................................27
Maintenance ..................................................................27
Troubleshooting ..............................................................27
Maintenance ...................................................................30
Specifications................................................................31
Dimensions....................................................................33
7
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8
Introduction
Special Design Features
Design Principles
Dear Customer, thank you for purchasing Tersicore stereo
power amplifier. Tersicore combines the power and current
delivery of larger high performance amplifiers with the small
form factor of a small power amplifier. Tersicore delivers great
sound which only the best product can deliver and has an
original and captivating look.
Below you can find a description of all the features that make
Tersicore a unique and valued product.
Customizable
external shell
Tersicore, like all Absoluta products, features an external
removable shell, that can be easily replaced, to adapt the look of
the amplifier to the room’s furniture style and to better match
the owner’s taste. The shell is available in various finishes, but
the customer can require custom versions, choosing amongst
several materials and colors.
Highest class
components
Tersicore is made with first-class components, like the massive
low stray flux and large bandwidth power transformers, the
main reservoir capacitors with high capacity and low parasitic
inductance, low tolerance polypropylene capacitors and special
low noise resistors for audio use.
The double layer printed circuit boards are made with high
thickness copper (105um in place of the usual 35um) to lower
tracks resistance and inductance, particularly those which carry
relevant current. The connections which carry the highest
currents are made with suitable wires to reduce impedance to a
minimum. This choice makes for a very low impedance supply
capable to support the needs of the high current circuit of the
amplifier, up to the upper frequency limit and at full power.
Current gain
technology
Absoluta has chosen, for her power amplifiers, to adopt the
current gain technology for the signal amplification chain,
instead of the traditional voltage gain technology. The
advantages of the choice made by Absoluta are numerous and
can be read within Tersicore specs: a very large power
bandwidth (That is the frequency response measured when the
amplifier is delivering
the rated power), a reduced rise time, capable of supporting the
9
Special Design Features – Design Principles (continued)
fastest transient at every listening level, and an intrinsic stability
on every load.
The large use of output devices (two 16A Sanken BJT for each
polarity) and the robustness of the power amplifier granted by
the two 350VA transformers allow for an exemplar behavior of
the Tersicore with every loudspeaker, even with impedances
less than 2Ω. Actually, The output stage of Tersicore behaves as
a real I-V converter, imposing to the load a faithful copy of the
current signal amplified by the signal chain.
“Diamond”
input stage
This sophisticated input stage is made following the “diamond”
topology, which allows for a high input impedance, absolute
linearity and intrinsic V-I conversion with nearly infinite
bandwidth and absence of any slew-rate effect. The input stage
offers both single-ended and balanced inputs.
In the case of the single-ended input both non-inverting and
inverting nodes are accessible. It is then possible to choose the
operation polarity of the amplifier following that of the
preamplifier and of the loudspeaker. It is also possible to make a
bridge connection of the two channels of Tersicore to obtain a
monoblock power amplifier capable of 300W on 8Ω, without
using inverting circuits.
Sophisticated and
non-intrusive
protections
Tersicore is provided with an exclusive and refined electronic
protection circuitry to grant the health of the output devices.
Differently from most of other products the protection circuit of
Tersicore is a sophisticated analog calculator that computes the
Ic * Vce product, obtaining the instant power dissipated on each
power transistor. With a bandwidth of 500kHz, the protection
circuit continuously patrols the power transistor dissipation and
activates only when the dissipation exceeds the borders of the
dynamic S.O.AR. (Safe Operating ARea) for long. The collector
current is monitored, too, to prevent it from exceeding its limit,
no matter how much power is dissipated by the transistor.
The power capability of the output transistors is such that
protections activate only in unlikely limit conditions (shortcircuits on the output or strongly reactive loads with impedance
module less than 1.5Ω). In the event of continuous overloads,
the protection circuit disconnects the load from the amplifier, to
guarantee amplifier’s operation.
The loudspeakers’ safety is guaranteed by a circuit which senses
the offset (direct current) on the speakers output, disconnecting
the load from the amplifier until the cause of the offset is
removed. The same circuit immediately disconnects the load
10
Special Design Features – Design Principles (continued)
when an abnormal dynamic condition occurs (for example,
when a interconnect is inserted on the amplifier input when it is
on).
The circuit is also effective when a fault or malfunction of the
amplification circuit occurs.
As further safety guarantee of the amplifier, a specific circuit
senses the temperature of the heat sinks and disconnects the load
(thus reducing the power dissipated by the output devices to a
minimum) when their temperature rises too much.
11
Unpacking
Warning!
DO NOT try to lift or move Tersicore without adequate
assistance. Failure to follow the procedures included in
this section may result in personal injuries and/or product
damage.
Tersicore is a heavy and massive amplifier. Its weight is 23.5kg
(52 lbs.) without packaging, 38kg (84 lbs.) with packaging.
Don’t get fooled by its small size: its weight is enough to cause
injuries to your spine, more so when it’s not possible to use a
correct lifting technique. Two people are required to lift and
shift Tersicore.
Warning!
DO NOT try to extract Tersicore from its packaging without
help.
DO NOT try to lift Tersicore while bending on it. When
lifting it, keep your back vertical as much as possible,
using your legs to lift the amplifier.
When extracting Tersicore from its packaging:
● DO save all packaging materials for possible future shipping
needs.
● Do inspect Tersicore for signs of damage during shipment.
If damage is discovered, contact an Absoluta authorized
dealer for assistance.
12
Installation Considerations
Tersicore requires special care during installation to ensure
optimal performance. Pay particular attention to the precautions
included in this section and to other precautions included
throughout this owner’s manual.
Placement
● DO review “Important Safety Instructions” and “Power
Requirements” before installing Tersicore.
● Do place Tersicore on a solid, flat, level surface, such as a
table, a shelf or the floor.
● DO position Tersicore close to the associated loudspeakers to
keep loudspeakers wires as short as possible. Use longer
interconnect cables between Tersicore and the preamplifier.
This is preferable because interconnect cables pass lowvoltage signals, which transmit over distances with greater
accuracy than the high-voltage signals required by loudspeakers.
● DO allow at least 15cm clearance behind Tersicore for the
power cord and other cables to bend without crimping or
straining.
● DO see “Dimensions” for assistance with custom
installation.
● DO NOT position Tersicore near low-level components. This
amplifier is capable of producing massive output currents
which could generate significant magnetic fields that could
induce noise in some sensitive components.
● DO NOT place Tersicore on a windowsill or in any other
location in which it will be exposed to direct sunlight. Solar
radiations can damage it or alter its color.
Warning!
BEFORE moving Tersicore, make sure it is powered off
using the power cocker switch on the back panel. Then,
make sure that the power cord is disconnected from the
AC mains connector and from the power outlet.
DO NOT attempt to move Tersicore without adequate
assistance. Proper lifting requires at least two people.
Ventilation
Tersicore dissipates the heat produced during operation through
two massive heat sinks placed laterally to the cabinet, and
thanks to several venting holes located on the bottom and on the
top of the cabinet. The hot air coming out of these holes finds it
way thanks to a particular design of the external shell.
Installation Consideration (continued)
13
When Tersicore is placed in a position in which a correct air
flow is provided, its proper operation is ensured at every
listening level and with every loudspeaker.
Due to the high bias of output devices, Tersicore produces
relevant heat even when idle. Heat sinks can become very hot
during high volume listening. Please consider that a temperature
of 60°C makes the heat sinks impossible to touch with bare
hands. Thermal protection triggers when heat sinks’ temperature
reaches 85°C.
● DO select a dry, well-ventilated position, out of direct
sunlight.
● DO NOT obstruct venting holes on the bottom and on the top
of the
cabinet or on the outer shell. Do not reduce air flow through
the cabinet and around the heat sinks.
● DO NOT place Tersicore on a thick carpet. Do not cover it
with a cloth, as this would impede proper cooling. If
Tersicore is placed on the floor, use a thick tempered glass
sheet to provide a stable base and to provide adequate
venting.
● DO NOT expose Tersicore to high temperature, humidity,
steam, smoke, dampness or excessive dust. Avoid installing
Tersicore near radiators and other heat-producing appliances.
14
Power Requirements
Tersicore is configured to operate at the voltage present in the
Country where it is sold. Before activating Tersicore, make sure
that the label on the back panel indicates the right mains
voltage.
Warning!
DO NOT attempt to adjust the operating voltage. Consult
an authorized Absoluta dealer if the operating voltage is
incorrect or if the operating voltage must be changed for
relocation purposes.
BE ADVISED that different operating voltages may require
the use of different power cords and/or attachment plugs.
Contact an authorized Absoluta dealer for assistance.
Tersicore is capable of passing remarkable musical signals
regardless of signal and of loudspeakers demands. On either an
instantaneous or continuous basis, this amplifier is capable of
driving exceptional power level into most of loudspeakers loads.
Depending on listening habits, loudspeakers demands and on
the number of power amplifiers present in the system – it is
possible for the electrical service to become the limiting
performance factor.
In this case, consider installing a dedicated AC circuit for the
home entertainment system. Contact a licensed electrician for
assistance. If more than one electric circuit is providing power
to the system, contact a licensed electrician to ensure that all
components are operating with the same, solid low-impedance
round reference.
Note
Building regulations and electrical codes differ from location to
location, making it impossible to anticipate the requirements of
high-current AC circuits such as Tersicore is capable of using.
Contact a local, licensed electrician for information.
Warm-up & break-in
period
Although Tersicore delivers superior performance from the first
time it’s powered on, its performance will continue to improve
as the power amplifier reaches its normal operating temperature
and various components “break-in”. The greatest performance
improvements will occur within the first 100 hours of use.
Sound quality will continue to improve for about 300 hours.
After this initial period, Tersicore performance will remain
consistent unless the unit is switched off. Once switched off,
after the successive switch-on, nearly half an hour will occur
before Tersicore will give the best performance again.
15
Power Requirements (continued)
Operating modes
Tersicore has three operating modes:
1. Off
Power is considered disconnected from Tersicore (back panel
Switch on “0” and trigger input not connected or power cord
disconnected).
2. Standby
The back panel switch in on “0”, the power cord is connected
to the power outlet and the trigger input is connected to the
trigger output of another device, but it’s not active.
Tersicore is not operative but can be switched on activating
the trigger output of the device to which the Tersicore trigger
input is connected.
3. On
The power cord is connected to the mains outlet and the back
Panel switch is on “1” and/or the trigger input is driven
(active) by the trigger output of another device.
Note
Continuous
operation
Tersicore is designed to operate with a high bias on the output
stage, for this reason it generates relevant heat even when idle.
Idle power consumption is 40W, which are dissipated as heat.
Tersicore should be unplugged from the mains outlet during
lightning storms and during extended periods of non-use.
Otherwise, it is designed for continuous operation.
Although Tersicore reaches its best performance after half an
hour of operation, it is better not to keep the unit continuously
on in order to have the best sound always available. This would
cause an unnecessary waste of electrical power, Tersicore would
be exposed to unnecessary risks and some of its fundamental
components would be subject to fast ageing.
16
Operation
Back Panel
The numbers in the back panel illustration shown above
correspond with the items in this section.
1,4. Non-inverting single-ended input connector
Non inverting unbalanced audio input. An RCA socket
accepts single-ended signals from a preamplifier.
Signal phase is maintained from Tersicore input to output
when using this connection. To minimize noise pick-up,
when using the inverting single-ended input connector it’s
better to short-circuit this connector with a shorting plug
2,3. Inverting single-ended input connector
Inverting unbalanced audio input. An RCA socket accepts
single-ended signals from a preamplifier.
Signal phase is inverted from Tersicore input to output
when using this connection. To minimize noise pick-up,
17
Back Panel (continued)
when using the non-inverting single-ended input connector
it’s better to short-circuit this connector with a shorting plug.
5,6. Balanced input connector
G
+
Balanced audio input. An XLR female connector accepts
balanced signals from a preamplifier. Tersicore offers the
highest level of performance whatever connection is used.
Whenever the distance between Tersicore and the
preamplifier is relevant (more than 5 meters or 15 feet) and/or
whenever remarkable EMI disturbances are present in the
room, the balanced connection provides superior rejection to
electromagnetic interferences (EMI).
-
Note
When using the balanced input, the shorting plugs MUST be
removed from the two single-ended input connectors
Note
Pay attention to the layout of hot and cold poles (“send” e
“return”) in the balanced output connector of the preamplifier
used with Tersicore. Two standards can be found, one used in
Japan and, sometimes, in the USA; the other used in Europe
and, often in the USA. The two standards differ in which hot
and cold poles are exchanged in the connectors. Absoluta
products comply to European standards. Should your
preamplifier adhere to Japanese standards, a phase reversal will
result from connecting the preamplifier to Tersicore, one which
can be recovered by inverting speakers cable polarity at
Tersicore output posts.
7,10. Positive output post
Power output positive post. A gold plated connector
accepts bare wire, bananas and spades lugs. Thanks to
the presence of an axial hole it is possible to simultaneously
connect two cables, one of which terminates with bananas,
in order to implement bi-wiring connection of the
loudspeaker. The large size of the connectors makes for best
current transfer from amplifier to loudspeaker.
Warning!
NEVER connect the positive power output to any
component other than to a loudspeaker
NEVER short-circuit the positive output to the negative one
or to any metal part of the amplifier.
8,9. Negative output post
Power output positive post. A gold plated connector
18
Back Panel (continued)
accepts bare wires, bananas and spades lugs. Thanks to
the presence of an axial hole it is possible to simultaneously
connect two cables, one of which terminates with bananas,
in order to implement bi-wiring connection of the
loudspeakers. The large size of the connectors makes for best
current transfer from amplifier to loudspeaker.
For best performance, use high-quality loudspeaker cables. Use
high quality terminations, soldered or accurately crimped at
cables ends to connect these cables
● Connect the positive output post of Tersicore to the positive
input of the loudspeaker. This input is generally associated
with red color.
● Connect the negative output post of Tersicore to the negative
inputof the loudspeaker. This input is generally associated
with black color.
Warning!
DO NOT OVER-TIGHTEN the binding posts. The specific
contact surfaces allow for a good contact even when the
posts are tightened by hand. No specific tool is required to
increase the tightening. Whenever a better contact is
required, please us expansion banana connectors.
DO NOT FORCE the posts to help the insertion of a
connector if its size or shape doesn’t fir the post: posts
may be damaged.
15. Trigger output connector
3,5mm jack socket for trigger output. A 12V DC voltage is
available on this output when Tersicore is on. Using this
output it is possible to activate another component provided
with a trigger input. For example, in a system in which two
Tersicore are used, one can be activated by the other by
connecting the trigger output of the first one to the trigger
input of the second one.
+
-
As the voltage is available on the trigger output after some
seconds from Tersicore activation, using the trigger to
activate the second amplifier avoids that switch-on surges of
the two units have place at the same time, reducing the risk
for the mains protection to trigger
The trigger output is protected against short-circuits and
Overloads by a polyswitch fuse. It’s always better to check
19
Back Panel (continued)
the polarity of the connection and not to overload the output
(refer to technical specs to find out the maximum output
current delivered by this output).
14. Trigger input connector
3,5mm jack socket for trigger input. By applying a 12V DC
voltage to this socket Tersicore is activated, no matter the
state of the power main switch. The trigger input and the
main power switch are in parallel, thus the trigger input is not
operative when the main power switch in on “1” (that is, it’s
not possible to switch the amplifier off but triggering the
main power switch)
Connect the trigger input of tersicore to the trigger output of a
Preamplifier or of another Tersicore.
Warning!
PAY ATTENTION to the polarity of the voltage applied to
the trigger input: it’s protected against polarity inversions,
but the trigger output of the driving unit could be damaged.
11. Main power switch
Switches Tersicore on ( “1” position) and off ( “0” position)
when the power cord is connected to a power outlet
and the trigger input is not active. In this case the amplifier
is always on regardless the switch’s state.
Note
The main power switch must be in “0” position (off) for the
trigger input to be operative.
12. Fuse holder
The fuse holder contains the main power fuse. Internal
circuits are already protected by other fuses located on the
printed circuit board. The fuse container in this fuse holder
only burns after critical events (huge amplifiers faults).
Should this happen, disconnect the power cord from the outlet
and contact an authorized Absoluta dealer for assistance.
Warning!
DO NOT try to replace the fuse.
Warning!
Potentially dangerous voltages and relevant charge are
present inside Tersicore even when the amplifier is off.
DO NOT try to open the amplifier’s cabinet to try servicing.
20
Back Panel (continued)
For all servicing refer to your authorized Absoluta dealer.
13. Mains socket
The mains socket provides the main power supply to
Tersicore when the power cord, provided with the amplifier,
is connected to it.
Note
Warning!
Before switching Tersicore on, make sure that the label on the
back panel showing the operating voltage indicates the right
voltage.
Tersicore has been designed and tested to be used with a
power cord provided with earth wire and with three prongs
plug. Do not damage or detach the earth prong from the
power cord plug.
21
Connections
Tersicore offers numerous options for connection to a
preamplifier and to loudspeakers.
Absolute phase
The absolute phase of the signal (e.g. the relationship between
the phase of the incoming signal from the preamplifier and that
of the signal applied to the loudspeaker) can either be
maintained or inverted depending on the input used and on the
polarity with which the loudspeakers are connected to the output
of the amplifier.
When using the non-inverting single-ended input or the
balanced input (European standard), absolute phase is
maintained by connecting the positive input of the loudspeaker
(red) to the positive output post of the amplifier and the negative
input of the loudspeaker (black) to the negative output of the
amplifier. By inverting this connection, absolute phase is
inverted, too (that is, your system becomes inverting).
Note
When using the inverting single-ended input or when driving
the balanced input with a preamplifier which balanced outputs
comply with the Japanese standard Tersicore becomes inverting,
thus the absolute phase needs to be restored by exchanging the
speakers cables’ connections either at amplifier’s outputs or at
loudspeaker’s inputs only.
The availability of an inverting input on Tersicore is useful
when using an inverting preamplifier (as many tube
preamplifiers are) because it allows for restoring absolute phase
by introducing a second phase inversion in the power amplifier.
Bi-wiring
Many loudspeakers give better performance when driven in biwiring. This technique requires the use of a pair of cables to
drive the low frequency section of the loudspeaker and another
pair of cables to drive its mid-high section. To implement this
technique it is necessary for the speakers to be provided with
two pairs of binding posts.
As Tersicore is provided with a single pair of output binding
posts, it is necessary to connect two cables to each post. It is
advisable to choose cables with terminations that don’t apply
excessive strain to the posts of the amplifier. A good choice
could be using bananas for one cable pair and spades for the
other, such as to use both connection modes offered by the
posts.
Warning!
Even if it’s possible to connect bare wires to the posts, it is
better not to choose this solution: chances are that some
22
Connections (continued)
conductors escape the tightenings and accidentally come
into contact with the metal parts of the amplifier or other
conductors from the other polarity cable, causing shortcircuits.
ALWAYS PREFERE cables provided with suitable
terminations.
Collegamento a
Bridging
ponte (bridging)
When a higher power than that provided by a single Tersicore is
necessary, it’s possible to connect two Tersicore channels in
bridge mode, obtaining a monoblock amplifier capable of
300Wrms continuous @ 8Ω and 600Wrms continuous @ 4Ω.
Connect the two Tersicore channels as follows:
● Connect the non-inverting input of the first Tersicore channel
to the output of the preamplifier.
● Connect the inverting input of the second Tersicore channel
to the same preamplifier’s output (a suitable splitter must be
used) or to a second output of the preamplifier on which the
same signal as the first output is present.
● Connect the positive input of the speaker to the positive
output of the first Tersicore channel.
● Connect the negative input of the speaker to the positive
output of the second Tersicore channel.
● Connect the two negative output posts of the two Tersicore
channels each other.
Nota
Note
Attenzione!
Warning!
If, by mistake, the same input (non-inverting or inverting) is
used on both channels of Tersicore, they will operate with the
same phase and the resulting signal on the loudspeakers posts
will be virtually zero. This will not damage either the
loudspeakers or the amplifiers.
DO NOT use loudspeakers with impedance less than 4Ω
with bridged Tersicore: in this set-up each channel “sees”
a load with impedance equal to half the impedence of the
loudspeakers and it’s required to supply twice as much
current than when it’s operating “alone”. This implies a
greater load on the output stage and could lead to
protection activation during music climaxes.
23
Connections (continued)
Base Connection Set-up
The basic connection configuration of Tersicore requires using
one Tersicore and one preamplifier (for example, Talia).
Connect the non-inverting input of each Tersicore channel to
one of the pre outputs of the preamplifier, one to the Left output
and one to the Right output using shielded cables with RCA
termination.
Connect the cables from each loudspeaker to the power output
of each channel of Tersicore, paying attention to the polarity.
If the trigger function is to be used, and when the preamplifier is
provided with a suitable output on a 3.5mm jack socket, connect
the preamplifier trigger output to the trigger input of Tersicore
using a interconnect provided with 3.5mm jack (mono or
stereo).
Note
To use Tersicore in inverting mode, connect the preamplifier
outputs to the inverting inputs of Tersicore.
Note
Short the unused inputs connector with the shorting plugs
provided with the amplifier. This reduces to a minimum the
noise pick-up from the unused input.
24
Base Balanced Connection
When the preamplifier is provided with balanced outputs with
XLR connections, it is possible to connect it to Tersicore in
balanced mode using balanced cables with XLR plugs.
This connection option is to be preferred when the power
amplifiers are far from the preamplifiers (more than 5m or 15ft)
and/or when the system is located in a room in which strong
electromagnetic disturbances are present.
Note
When using the balanced connection, the two single-ended input
connectors (RCA) must be left open.
Note
Depending on the standard of the preamplifier output XLR
connectors (European or Japanese), the signal phase may result
inverted at the input terminals of the loudspeakers. In this case,
it’s possible to restore the absolute phase either by inverting the
connection of the speakers cables at the amplifiers or
loudspeakers posts only or using the phase switch of the
preamplifier, when available.
Passive Bi-amping Connection
When the loudspeakers are provided with separate inputs for
low frequency and high frequency drivers, it is possible to
implement a passive bi-amping connection. This connection
mode requires one Tersicore per channel, driven by the same
output connector of the preamplifier (Left or Right) by a
suitable splitter, or by two different Left or Right outputs they
be available.
25
It is possible to make single-ended connections (using coax
cable and RCA connectors) or balanced connections (using
balanced cable and XLR connectors). For the specific
connections the previous indications hold true.
Bridge Connection
When speakers sensitivity and/or the size of the listening room
call for a higher output power than that delivered by a single
Tersicore, it is possible to use two connecting them in pair in
bridged mode. This set-up allows for three times as much power
as a single Tersicore, with a net gain of 5dB SPL.
By using Four Tersicore it is then possible to make a passive
bi-amping bridged configuration, following these indication
together with the previous ones (“Passive Bi-amping
Connection”).
26
Troubleshooting
Maintenance
Troubleshooting
A wrong use is sometimes mistaken for malfunction. Should
problems occur, refer to this section for troubleshooting. If
problems persist, contact your authorized Absoluta dealer.
1. The amplifier does not turn on (turn-on is indicated, a
few seconds after activation, by a “click” from each
internal output relay).
● Check for mains power cord correct insertion in the Tersicore
mains socket.
● Check for mains power cord plug correct insertion in the
mains outlet.
● Check for power cord integrity.
● Make sure that the main power switch is on “1” or that the
trigger input is driven with a 12 V DC voltage with the
correct polarity.
● Check for mains fuse integrity.
● It is possible that one of the internal fuse is s blown. In this
case, disconnect the unit from the power outlet and contact
your authorized Absoluta dealer. DO NOT try to replace
any fuse. Nor any other serviceable parts inside the unit.
Warning!
Potentially dangerous voltages are present inside
Tersicore, even when the unit is off. DO NOT try any
servicing inside the unit. DO NOT open the unit. Contact
your authorized Absoluta dealer for servicing.
2. The amplifier turns on (turn-on is indicated, a few
seconds after activation, by a “click” from each internal
relay but no sound comes from the loudspeakers.
● Make sure that the cables of the loudspeakers are correctly
connected to
27
Troubleshooting (continued)
the output posts of Tersicore.
● Make sure that the interconnect cables are correctly
connected to the input of Tersicore and to the preamplifier
output.
● Make sure that the preamplifier is on.
● Check for integrity of all interconnect and power cables used
with Tersicore.
● It is possible that Tersicore goes into protection right after
activation due to a short-circuit on output of the speakers.
It is possible to check this by carefully listening to the
relay “clicks”: if more clicks are heard right after the first
two, chances are that the protection circuit of the amplifier
has sensed a short-circuit on the output of the amplifier.
Remove the short-circuit.
Warning!
When discovering that one of the cables (interconnect or
power) is not correctly connected, switch Tersicore off
before completing the connection. NEVER connect or
disconnect a cable when Tersicore is on! This could
damage the amplifier or the loudspeakers.
3. The output relays disengage every time the preamplifier
is turned on or when a certain source is selected, to reengage after a few seconds.
● DC offset is present on preamplifier or source output.
Tersicore is able to null this offset, but its presence at the
input of the amplifier may result in a reduction of the quality
of the sound and in excessive heating of Tersicore. Contact
the dealer who sold the preamplifier or the source for
servicing.
4. The amplifier doesn’t turn on by the trigger input.
● Check for correct connection and polarity of the cable
between the trigger output of the preamplifier and the trigger
input of Tersicore.
5. The voltage at the Tersicore trigger output doesn’t reach
the component to which the output is connected.
● Check for integrity of the cable used to take the trigger
voltage from Tersicore to the input of the component.
● Check for magnitude and polarity of the voltage required to
activate the component to be activated by Tersicore.
28
Troubleshooting (continued)
6. The sound produced by Tersicore is distorted at high
levels.
● The loudspeakers used with Tersicore and/or the size of the
room require more power than that delivered by Tersicore.
Use two Tersicore in bridged set-up or try bi-amping.
7. Tersicore overheats and/or thermal protections engages
frequently.
● The unit is not properly ventilated or it’s placed in an
excessively hot room. Allow for more free room around, over
and under the unit to increase ventilation and/or move it to a
cooler place.
● The unit is constantly overdriven on a very difficult load.
Reduce listening level or add a second Tersicore (in bridged
or bi-amp set-up)
● A relevant DC offset is present on Tersicore input (see item
3 to solve this problem).
● The unit is damaged. Switch Tersicore off and contact your
authorized Absoluta dealer.
8. A light electric shock is perceived when touching the
exposed metal parts of Tersicore when it is connected to
the mains.
● Tersicore earth connection is faulty. Switch the unit off,
disconnect it from mains and contact your authorized
Absoluta dealer.
● Your house mains network is not provided with safety
earth, or the mains outlet you’re using is not provided with
earth connection. Contact a licensed electrician to solve this
problem.
Warning!
DO NOT, for any reason, disconnect or eliminate the earth
connection of mains outlets, power distributors of power
cords. Tersicore has been designed to provide top
performance and safety with an earth connection. Using
the unit without an adequate earth connection may result
in damage to the unit or to other components connected to
it. It may harm or cause the death of whoever gets in touch
with the unit metal parts!
29
Troubleshooting (continued)
In all other cases not covered by this section, switch unit off and
disconnect from mains outlet and from all other components of
the system. Contact your authorized Absoluta dealer for
assistance.
Maintenance
Attenzione!
Tersicore has been designed to give his owner years of troublefree use. The unit doesn’t require any maintenance on a regular
basis, nor adjustments of any kind.
The only maintenance operation to be done on a regular basis is
the one required by outer shell, to remove dust and fingerprints.
Failing to follow the indications in this section may result in
damages to the unit and warranty voiding.
● Use a feather duster or a low pressure blower to remove dust
from the surface and from the heat sinks.
Nota
● Use a soft, lint-free cloth to remove dirt and fingerprints
from the surface. DO NOT use a cloth made
with steel wool or metal polish.
● When needed, the cloth can be dampened with isopropyl
alcohol to clean metal parts. DO NOT use acetone, benzene
and other commercial cleaners.
● The outer shell must be treated, depending on the material
it’s made of and depending on its finish, with the cleaner
recommended
by the manufacturer (the indication is given together with the
shell, on a separate sheet).
Warning!
DO NOT drop or apply liquids directly onto the unit,
because this could damage the internal components and
impede the unit’s proper operation.
30
Specifications
Rated Output Power
● 100Wrms p.c. @ 8Ω
● 200Wrms p.c. @ 4Ω
● 350Wrms p.c. @ 2Ω
All rated power values are 10Hz to 200kHz, with a THD less
than 0.1% e at nominal mains voltage. Any load phase.
Measured Ouput
Power
● 126Wrms p.c. @ 8Ω
● 210Wrms p.c. @ 4Ω
Power measured @ 1kHz, on resistive load, with THD less than
0.1% at nominal mains voltage.
Peak Current
Frequency
Response
Signal-to-Noise
Ratio
THD + N
Input Impedance
● 32A (10ms)
● 20Hz to 20kHz +/-0,1dB
● 10Hz to 250kHz +/-3dB
● 85dB not weighted
● 88dB “A” weighted (ref. nominal output voltage)
0,04% (@ 2,83Vrms output)
● 47kΩ (unbalanced)
● 100kΩ (balanced)
Gain
Sensitivity
● 26dB
● 1,41Vrms for rated output power
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Specifications (continued)
Power Consumption
● 700VA (+/-5%) max. output power
● 40VA (+/-5%) idle
Mains Voltage
Size
Weigth
● Fixed as indicated by the label on the back panel
● 270 x 144.5 x 429.8 mm (see “Dimensions”)
● With packing: 38kg
● Net: 23.5kg
Connectors
● 4 gold plated output binding posts for loudspeaker
● 4 gold plated RCA input connectors
● 2 female XLR balanced input connector
● 2 mini-jack (3.5mm) connectors for triggers
● 1 IEC mains socket
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Dimensions
s
Dimension
33